US6461478B1ExpiredUtility
Method and device for treating a fibrous material web
Assignee: VOITH SULZER PAPIERTECH PATENTPriority: Jan 24, 1997Filed: Jan 23, 1998Granted: Oct 8, 2002
Est. expiryJan 24, 2017(expired)· nominal 20-yr term from priority
Inventors:Andreas Meschenmoser
D21F 3/045
35
PatentIndex Score
2
Cited by
17
References
75
Claims
Abstract
Disclosed is method and a pressing device ( 10 ) of a paper and/or paperboard machine intended for the treatment of a fibrous web ( 12 ) which is formed on a band screen and passes around an appropriate open roller ( 16 ) having recessed intended to receive the water squeezed out the fibrous web. The open roller forms with a counterface a first nip ( 18 ) which is extended, in the direction of movement of the L band, by a pressing shoe unit ( 20 ). A papermaker's felt ( 22, 24 ) passes both on the open roller ( 16 ) and said pressing shoe unit ( 20 ).
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. A pressing device for treating a fibrous material web comprising:
a band screen for carrying the material web which is formed upon it;
an open roll comprising recesses for receiving water pressed out of the material web;
a first nip extended in a web running direction being formed between the open roll and a counter-surface comprising a pressing shoe unit;
at least one of the open roll and a suction device being provided to suction the material web on the band screen;
an open roll felt belt being guided over the open roll and a pressing shoe felt belt being guided over the pressing shoe unit;
a second nip arranged downstream the first nip; and
another felt belt arranged to travel through the second nip with the material web,
wherein the pressing shoe felt belt is separated from the material web while the material web and the band screen is suctioned, and
wherein the material web is removed from the band screen between the first and second nips by one of a smooth belt and a smooth roll.
2. The device of claim 1 , wherein the pressing shoe unit associated with the open roll is a shoe pressing roll.
3. The device of claim 1 , wherein the open roll comprises a surface having at least one of grooves and blind bores, said open roll further comprising a non-permeable press roll jacket lying beneath the surface.
4. The device of claim 1 , wherein the open roll is a suction roll and includes a roll jacket provided with a plurality of radial bores which are not through-bores;
wherein the open roll is internally suctioned.
5. The device of claim 3 , further comprising a gutter adapted to capture led-away spun-off water, wherein the open roll is at least partly surrounded by the gutter.
6. The device of claim 1 , wherein the open roll is a roll tube having a plurality of radial bores which are not through-bores, and wherein the open roll is externally suctioned.
7. The device of claim 6 , further comprising an outer suction box which surrounds a portion of the open roll but which is not in contact with the open roll felt belt that is guided over the open roll.
8. The device of claim 7 , wherein the suction box comprises an end section having a suction opening adjacent the open roll, and wherein the end section is arranged to be substantially parallel to a pressing plane;
wherein the open roll projects at least partly through the suction opening into the end section;
wherein at least substantially an entire part of the open roll located outside of the suction box is surrounded by the open roll felt belt, and wherein the open roll felt belt is supported by an outer surface of the end section which is located adjacent to but not in contact with the open roll.
9. The device of claim 8 , wherein the open roll felt belt is guided symmetrically to a pressing plane of the first nip about the open roll and about the end section of the suction box.
10. The device of claim 1 , wherein the band screen and the fibrous web are guided away from the open roll at an angle of at least 2° relative to the open roll felt belt.
11. The device of claim 2 , wherein the shoe pressing roll comprises a flexible pressing jacket having an outer surface having recesses for receiving pressed-out water from the fibrous web, thereby facilitating even dewatering of the fibrous material web at the first nip, and
wherein even dewatering results on both sides of the fibrous web when the first nip comprises: the jacket surface; a water permeable felt belt; a water permeable band screen; a water permeable open roll felt belt; and the roll surface.
12. The device of claim 11 , wherein the shoe pressing roll is at least partly surrounded by a gutter for capturing and leading away the spun-off water from the recesses of the flexible pressing jacket.
13. The device of claim 1 , wherein the second nip is formed by a press roll and a counter-surface.
14. The device of claim 13 , wherein the material web is guided, after leaving the second nip, on the smooth belt to a further process section which is directly without an open web run,
wherein the further process section includes a drying cylinder.
15. The device of claim 1 , wherein the second nip is formed by a pressing shoe arrangement which is extended in the web running direction.
16. The device of claim 15 , wherein the pressing shoe arrangement comprises a shoe press roll and a counter-surface.
17. The device of claim 13 , wherein at least one of the press roll and the counter-surface, comprises a roll jacket which is supported by at least one support element against the other of the at least one of the press roll and the counter-surface.
18. The device of claim 13 , wherein the press roll and the counter-surface both comprise pressing shoe rolls with flexible pressing jackets having substantially planar pressing surfaces.
19. The device of claim 1 , wherein the smooth roll comprises a flexible pressing jacket adapted to directly remove the fibrous material web from the band screen, and adapted to supply the material web directly to the second nip, wherein the second nip is formed by a pressing shoe roll and a counter-roll, and the other felt belt is wrapped around the counter roll.
20. The device of claim 19 , wherein the flexible pressing jacket of the shoe pressing roll transfers the fibrous material web adhering to it to a further process section, after leaving the second nip, directly without an open web run.
21. The device of claim 1 , wherein the second nip comprises a pressing shoe roll having a rigid smooth jacket such that the pressing shoe roll removes the fibrous material web directly from the band screen without the participation of any belts, and such that the pressing shoe roll supplies the web directly to the second nip, which is formed by the pressing shoe roll and an opposing pressing shoe roll, around which the other felt belt extends.
22. The device of claim 21 , wherein the jacket of the pressing shoe roll transfers the fibrous material web adhering to it after leaving the second nip to a further process section, directly without an open web run.
23. The device of claim 1 , further comprising a spraying device for moistening at least one of the smooth belt and the smooth roll;
wherein the moistening facilitates the removal of the fibrous material web and wherein the moistening is accomplished with one of water and suitable chemicals in order to achieve a reliable adhesion of the fibrous material web.
24. The device of claim 4 , wherein the open roll is surrounded at least partly by a gutter in order to capture led-away, spun-off water.
25. The pressing device of claim 1 , wherein the pressing device is for one of a paper and paperboard machine.
26. The device of claim 1 , wherein the open roll is a suction roll and includes a roll jacket provided with a plurality of radial bores which include radial through-bores;
wherein the open roll is subjected to internal suction.
27. The device of claim 1 , wherein the open roll is a roll tube having a plurality of radial through-holes, and wherein the open roll is subjected to external suction.
28. The device of claim 1 , wherein the smooth belt is guided, after leaving the second nip, so that it transfers the fibrous material web adhering to the smooth belt to a further process section, including a drying cylinder, which is indirectly without an open web run.
29. The device of claim 20 , wherein the further process section comprises a dryer cylinder.
30. The device of claim 19 , wherein the flexible pressing jacket of the shoe pressing roll transfers the fibrous material web adhering to it to a further process section, after leaving the second nip, indirectly without an open web run.
31. The device of claim 22 , wherein the further process section comprises a dryer cylinder.
32. The device of claim 21 , wherein the jacket of the pressing shoe roll transfers the fibrous material web adhering to it after leaving the second nip to a further process section indirectly without an open web run.
33. A pressing device for treating a fibrous material web comprising:
a band screen for carrying the material web which is formed upon it;
an open roll comprising recesses for receiving water pressed out of the material web;
a first nip extended in a web running direction being formed between the open roll and a counter-surface comprising a pressing shoe unit;
at least one of the open roll and a suction device being provided to suction the material web on the band screen;
an open roll felt belt being guided over the open roll and a pressing shoe felt belt being guided over the pressing shoe unit;
the pressing shoe felt belt and the material web being separated from each other after the material web is suctioned;
the band screen and the fibrous web being guided away from the open roll at an angle of at least 2° relative to the open roll felt belt; and
a separating suction device provided adjacent the band screen and positioned on the side of the open roll where the open roll felt belt separates from the band screen,
wherein the separating suction device applies a vacuum suction to the fibrous web in order to dewater the fibrous web together with the band screen; and
wherein the separating suction device leads away spun-off water originating from a wedge space defined by the position where the open roll felt belt and band screen separate, such that the separating suction device utilizes a front edge which acts as a deflector strip and extends into the wedge space between the band screen and the open roll felt belt.
34. The device of claim 33 , wherein the separating suction device further comprises a gutter located transversely to the web running direction for receiving and leading away the spun-off water which is picked up ahead of the deflector strip of the suction separating device.
35. The device of claim 11 , wherein the recesses are blind bores.
36. A method of treating a fibrous material web in a pressing device comprising:
forming and carrying the material web upon a band screen;
forming a first nip between an open roll and a counter-surface, wherein the first nip is extended in a web running direction, the counter-surface is formed with a pressing shoe unit, and the open roll includes recesses;
guiding an open roll felt belt over the open roll;
guiding a pressing shoe felt belt over the pressing shoe unit;
guiding the material web through the first nip, which presses water out of the material web;
suctioning the material web on the band screen using one of the open roll and a suction device;
receiving the water pressed out of the material web in the recesses;
separating the pressing shoe felt belt from the material web while the material web and the band screen is subjected to suctioning;
removing the material web from the band screen via one of a smooth belt and a smooth roll; and
guiding the material web and another felt belt through a second nip via one of the smooth belt and the smooth roll.
37. The method of claim 36 , further comprising:
evacuating the open roll from the inside without a through-bored cover.
38. The method of claim 36 , further comprising:
capturing led-away, spun-off water by a gutter surrounding the open roll.
39. The method of claim 36 , further comprising:
evacuating the open roll from the outside, without a cover having through holes.
40. The method of claim 36 , wherein the open roll felt belt is guided symmetrically to the plane of pressing of the first nip about the open roll and about the end section of the suction box.
41. The method of claim 36 , further comprising:
picking up pressed-out water of the fibrous web in order to facilitate even dewatering of the fibrous material web at the first nip by way of a shoe pressing roll which comprises a flexible pressing jacket having an outer surface which has recesses; and
providing for even dewatering on both sides of the fibrous web by moving the following through the first nip: a water permeable felt belt; a water permeable band screen; and a water permeable open roll felt belt.
42. The method of claim 36 , further comprising guiding the web over a press roll of the second nip, the second nip being formed by the press roll and a counter-surface.
43. The method of claim 42 , further comprising bringing one of the smooth belt and the smooth roll into contact with the band screen for separating the fibrous material web and simultaneously forming the second nip with a counter-surface.
44. The method of claim 43 , further comprising guiding the smooth belt after leaving the second nip so that it transfers the fibrous material web adhering to the smooth belt to a further process section, such as a drying cylinder which is directly without an open web run.
45. The method of claim 36 , wherein the second nip comprises a pressing shoe arrangement extending in the web running direction.
46. The method of claim 36 , wherein the pressing further comprises spraying for moistening at least one of the smooth belt and the smooth roll;
wherein the moistening facilitates the separation of the fibrous material web and wherein the moistening is accomplished with one of water or suitable chemicals in order to achieve a reliable adhesion of the fibrous material web.
47. A method of treating a fibrous material web in a pressing device comprising:
forming and carrying the material web upon a band screen;
forming a first nip between an open roll and a counter-surface, wherein the first nip is extended in a web running direction, the counter-surface is formed with a pressing shoe unit, and the open roll includes recesses;
guiding an open roll felt belt over the open roll;
guiding a pressing shoe felt belt over the pressing shoe unit;
guiding the material web through the first nip, which presses water out of the material web;
suctioning the material web on the band screen using one of the open roll and a separating suction device;
receiving the water pressed out of the material web in the recesses;
separating the pressing shoe felt belt from the material web after the suctioning;
separating through the separating suction device the open roll felt belt from the band screen;
applying a vacuum suction on the fibrous web in order to dewater the fibrous web together with the band screen; and
leading away spun-off water originating from a wedge space defined by the position where the open roll felt belt and the band screen separate such that the separating suction device utilizes a front edge which acts as a deflector strip and extends into the wedge space between the band screen and the open roll felt belt.
48. A method of treating a fibrous material web in a pressing device comprising:
forming and carrying the material web upon a band screen;
forming a first nip between an open roll and a counter-surface, wherein the first nip is extended in a web running direction, the counter-surface is formed with a pressing shoe unit, and the open roll includes recesses;
guiding an open roll felt belt over the open roll;
guiding a pressing shoe felt belt over the pressing shoe unit;
evacuating the open roll;
guiding the material web through the first nip, which presses water out of the material web;
suctioning the material web on the band screen;
separating the pressing shoe felt belt from the material web while the material web and the band screen is subjected to suctioning;
receiving the water pressed out of the material web in a gutter which surrounds the open roll;
separating the open roll felt belt from the band screen after the first nip;
removing the material web from the band screen via one of a smooth belt and a smooth roll; and
guiding the material web and another felt belt through a second nip via one of the smooth belt and the smooth roll.
49. A pressing device for treating a fibrous material web comprising:
a band screen for carrying the fibrous material web;
a roll;
a suction device associated with the roll;
a gutter surrounding the roll for capturing led-away, spun-off water;
an extended first nip which is formed between the roll and a pressing shoe unit;
a roll felt belt which is guided over the roll;
a pressing shoe felt belt which is guided over the pressing shoe unit;
the pressing shoe felt belt being separated from the fibrous material web while the material web and the band screen is subjected to suctioning;
a second nip through which a smooth belt and the material web pass after the fibrous material web separates from the band screen via the smooth belt;
the second nip being arranged downstream the extended first nip;
another felt belt and the smooth belt arranged to travel through the second nip with the material web disposed therebetween;
a spraying device for moistening the fibrous material web; and
a drying cylinder for drying the fibrous material web,
wherein the fibrous material web is removed from the band screen between the extended first nip and the second nip by the smooth belt.
50. A pressing device for treating a fibrous material web comprising:
a band screen for carrying the material web which is formed upon it;
an open roll comprising recesses for receiving water pressed out of the material web;
a first nip extended in a web running direction being formed between the open roll and a counter-surface comprising a pressing shoe unit;
the open roll being arranged obliquely beneath the pressing shoe unit;
at least one of the open roll and a suction device being provided to suction the material web on the band screen;
an open roll felt belt being guided over the open roll and a pressing shoe felt belt being guided over the pressing shoe unit;
a second nip arranged downstream the first nip; and
another felt belt arranged to travel through the second nip with the material web,
wherein the pressing shoe felt belt is separated from the material web while the material web and the band screen is suctioned, and
wherein the material web is removed from the band screen between the first and second nips by one of a smooth belt and a smooth roll.
51. The device of claim 50 , wherein the open roll is a suction roll and includes a roll jacket provided with a plurality of radial bores which are not through-bores.
52. The device of claim 50 , further comprising a gutter adapted to capture led-away spun-off water, wherein the open roll is at least partly surrounded by the gutter.
53. The device of claim 50 , further comprising an outer suction box which surrounds a portion of the open roll but which is not in contact with the open roll felt belt that is guided over the open roll.
54. The device of claim 53 , wherein the suction box comprises an end section having a suction opening adjacent the open roll, and wherein the end section is arranged to be substantially parallel to a pressing plane;
wherein the open roll projects at least partly through the suction opening into the end section;
wherein at least substantially an entire part of the open roll located outside of the suction box is surrounded by the open roll felt belt, and wherein the open roll felt belt is supported by an outer surface of the end section which is located adjacent to but not in contact with the open roll.
55. The device of claim 50 , wherein the band screen and the fibrous web are guided away from the open roll at an angle of at least 2° relative to the open roll felt belt.
56. The device of claim 55 , further comprising a separating suction device provided adjacent the band screen and positioned on the side of the open roll where the open roll felt belt separates from the band screen;
wherein the separating suction device applies a vacuum suction to the fibrous web in order to dewater the fibrous web together with the screen band; and
wherein the separating suction device leads away spun-off water originating from a wedge space defined by the position where the open roll felt belt and band screen separate, such that the separating suction device utilizes a front edge which acts as a deflector strip and extends into the wedge space between the band screen and the open roll felt belt.
57. The device of claim 56 , wherein the separating suction device further comprises a gutter located transversely to the web running direction for receiving and leading away the spun-off water which is picked up ahead of the deflector strip of the suction separating device.
58. A method of treating a fibrous material web in a pressing device comprising:
forming and carrying the material web upon a band screen;
forming a first nip between an open roll and a counter-surface, wherein the first nip is extended in a web running direction, the counter-surface is formed with a pressing shoe unit, and the open roll includes recesses, and wherein the open roll is arranged obliquely beneath the pressing shoe unit;
guiding an open roll felt belt over the open roll;
guiding a pressing shoe felt belt over the pressing shoe unit;
guiding the material web through the first nip, which presses water out of the material web;
suctioning the material web on the band screen using one of the open roll and a suction device;
receiving the water pressed out of the material web in the recesses;
separating the pressing shoe felt belt from the material web while the material web and the band screen is subjected to suctioning;
removing the material web from the band screen via one of a smooth belt and a smooth roll; and
guiding the material web and another felt belt through a second nip via one of the smooth belt and the smooth roll.
59. The method of claim 58 , further comprising: evacuating the open roll from the inside.
60. The method of claim 58 , further comprising:
capturing led-away, spun-off water by a gutter surrounding the open roll.
61. The method of claim 58 , further comprising:
evacuating the open roll from the outside, without a cover having through holes.
62. The method of claim 58 , wherein the open roll felt belt is guided symmetrically to the plane of pressing of the first nip about the open roll and about the end section of the suction box.
63. The method of claim 58 , further comprising:
picking up pressed-out water of the fibrous web in order to facilitate even dewatering of the fibrous material web at the first nip by way of a shoe pressing roll which comprises a flexible pressing jacket having an outer surface which has recesses; and
providing for even dewatering on both sides of the fibrous web.
64. A method of treating a fibrous material web in a pressing device comprising:
forming and carrying the material web upon a band screen;
forming a first nip between an open roll and a counter-surface, wherein the first nip is extended in a web running direction, the counter-surface is formed with a pressing shoe unit, and the open roll includes recesses, and wherein the open roll is arranged obliquely beneath the pressing shoe unit;
guiding an open roll felt belt over the open roll;
guiding a pressing shoe felt belt over the pressing shoe unit;
guiding the material web through the first nip, which presses water out of the material web;
suctioning the material web on the band screen using one of the open roll and a suction device;
receiving the water pressed out of the material web in the recesses;
separating the pressing shoe felt belt from the material web after the suctioning;
separating via a suction device the open roll felt belt from the band screen;
applying a vacuum suction on the fibrous web in order to dewater the fibrous web together with the band screen; and
leading away spun-off water originating from a wedge space defined by the position where the open roll felt belt and the band screen separate such that the suction device utilizes a front edge which acts as a deflector strip and extends into the wedge space between the band screen and the open roll felt belt.
65. A pressing device for treating a fibrous material web comprising:
a band screen for carrying the material web which is formed upon it;
a roll comprising recesses for receiving water pressed out of the material web;
a first nip extended in a web running direction being formed between the roll and a counter-surface comprising a pressing shoe unit;
the roll being arranged obliquely beneath the pressing shoe unit;
a suction device for suctioning the material web on the band screen;
a roll felt belt being guided over the roll and a pressing shoe felt belt being guided over the pressing shoe unit;
a second nip arranged downstream the first nip; and
another felt belt arranged to travel through the second nip with the material web,
wherein the pressing shoe felt belt is separated from the material web while the material web and the band screen is suctioned, and
wherein the material web is removed from the band screen between the first and second nips by one of a smooth belt and a smooth roll.
66. The device of claim 65 , further comprising a gutter adapted to capture led-away spun-off water, the roll being at least partly surrounded by the gutter.
67. A pressing device for treating a fibrous material web comprising:
a band screen for carrying the material web which is formed upon it;
a roll comprising recesses for receiving water pressed out of the material web;
a first nip extended in a web running direction being formed between the roll and a counter-surface comprising a pressing shoe unit;
the roll being arranged obliquely beneath the pressing shoe unit;
a suction device for suctioning the material web on the band screen;
a roll felt belt being guided over the roll and a pressing shoe felt belt being guided over the pressing shoe unit;
the pressing shoe felt belt and the material web being separated from each other after the material web is suctioned; and
the suction device being provided adjacent the band screen and being positioned on the side of the roll where the roll felt belt separates from the band screen,
wherein the suction device applies a vacuum suction to the fibrous web in order to dewater the fibrous web together with the band screen, and
wherein the suction device leads away spun-off water originating from a wedge space defined by the position where the roll felt belt and the band screen separate, such that the suction device utilizes a front edge which acts as a deflector strip and extends into the wedge space between the band screen and the roll felt belt.
68. The device of claim 67 , wherein the separating suction device further comprises a gutter located transversely to the web running direction for receiving and leading away the spun-off water which is picked up ahead of the deflector strip of the suction separating device.
69. A method of treating a fibrous material web in a pressing device comprising:
forming and carrying the material web upon a band screen;
forming a first nip between a roll and a counter-surface, wherein the first nip is extended in a web running direction, the counter-surface is formed with a pressing shoe unit, and the roll includes recesses, and wherein the roll is arranged obliquely beneath the pressing shoe unit;
guiding a roll felt belt over the roll;
guiding a pressing shoe felt belt over the pressing shoe unit;
guiding the material web through the first nip, which presses water out of the material web;
suctioning the material web on the band screen using a suction device;
receiving the water pressed out of the material web in the recesses;
separating the pressing shoe felt belt from the material web while the material web and the band screen is subjected to suctioning;
removing the material web from the band screen via one of a smooth belt and a smooth roll; and
guiding the material web and another felt belt through a second nip via one of the smooth belt and the smooth roll.
70. The method of claim 69 , further comprising:
capturing led-away, spun-off water by a gutter surrounding the roll.
71. The method of claim 69 , further comprising:
evacuating the roll from the outside, without a cover having through holes.
72. The method of claim 69 , further comprising:
separating using the suction device the roll felt belt from the band screen;
applying a vacuum suction on the fibrous web in order to dewater the fibrous web together with the band screen; and
leading away spun-off water originating from a wedge space defined by the position where the roll felt belt and band screen separate such that the separating suction device utilizes a front edge which acts as a deflector strip and extends into the wedge space between the band screen and the roll felt belt.
73. The method of claim 69 , further comprising:
picking up pressed-out water of the fibrous web in order to facilitate even dewatering of the fibrous material web at the first nip by way of a shoe pressing roll which comprises a flexible pressing jacket having an outer surface which has recesses; and
providing for even dewatering on both sides of the fibrous web.
74. A pressing device for treating a fibrous material web comprising:
a band screen for carrying the material web which is formed upon it;
a first nip extended in a web running direction being formed between a roll and a counter-surface comprising a pressing shoe unit;
the roll being arranged obliquely beneath the pressing shoe unit;
a suction device being provided to suction the material web on the band screen;
a roll felt belt being guided over the roll and a pressing shoe felt belt being guided over the pressing shoe unit;
a spraying device;
a press roll arranged to remove the material web from the band screen;
a second nip arranged downstream the first nip; and
another felt belt arranged to travel through the second nip with the material web,
wherein the pressing shoe felt belt is separated from the material web while the material web and the band screen is suctioned, and
wherein the material web is removed from the band screen between the first and second nips by one of a smooth belt and a smooth roll.
75. A method of treating a fibrous material web in a pressing device comprising:
forming and carrying the material web upon a band screen;
forming a first nip between a roll and a counter-surface, wherein the first nip is extended in a web running direction, the counter-surface is formed with a pressing shoe unit, and the roll is arranged obliquely beneath the pressing shoe unit;
guiding a roll felt belt over the roll;
guiding a pressing shoe felt belt over the pressing shoe unit;
guiding the material web through the first nip, which presses water out of the material web;
suctioning the material web on the band screen;
separating the pressing shoe felt belt from the material web while the material web and the band screen is subjected to suctioning;
receiving the water pressed out of the material web in a gutter arranged adjacent the roll;
separating the roll felt belt from the band screen after the first nip;
spraying the material web using a spraying device;
removing the material web from the band screen via one of a smooth belt and a smooth roll; and
guiding the material web and another felt belt through a second nip via one of the smooth belt and the smooth roll.Cited by (0)
No later patents cite this yet.
References (0)
No backward citations on record.